Does anyone know of any software that one could run a cash flow split analysis for a joint venture?

That $10K would be all available, or the IRA could joint venture with another investor not considered a disqualified party to your IRA (you, spouse, lineal family).An IRA may borrow, but must use a non-recourse loan, meaning no personal guarantee from you or a disqualified party. 

Idea...Have mom list her home, sell it, put the proceeds in the bank in a joint account with you on account.The wait a few months, then purchase another property as an Investment Property with 20% down.Move mom into it, remove yourself from her account, then do a Lease Purchase, (record the lease) structuring it with you giving a credit to pay closing costs and after 12 months of having her making payments to you,  have her refi into her name.  

It's important to determine what you are looking for in your ROI numbers especially if you plan on Joint Venturing these out.

I started by doing joint ventures with homeowners, contractors, investors, etc.

I think the legal term is jointly and severally, but I'm no lawyer, this is not legal advice, and I could be totally wrong about the terminology.That way you go after both of them until you get paid, or whoever has the money.And I'd NEVER let someone move in who is not on the lease. 

If the rent is $1200 pm and two people apply they should both be earning at least $1800 pm, £3,600 joint monthly income.

I suspect those players are going to keep the best notes for their fund as is their fiduciary responsibility to the fund and their clients.. and then off load the ones they deem inferior for what ever reason to those like you

I have looked into adding my name to the deed as joint tenants, or tenants in common but my biggest concern is that if anything were to go wrong (e.g. while renting it out), my dad’s name would still be on the deed and therefore still partially liable (I would like to assume full legal liability).

Here's where it gets odd.Jack wants me to be the sole borrower on the property, on our joint project.Jack wants me to not tell the bank about my source of rehab funds because it'll "complicate things with the bank"The bank has capped my borrowing limit at $250,000, which is above the necessary $295,000 to do the deal.As a workaround, Jack will be the sole provider of rehab funds (personal funds, cash)Jack wants me to give him one of my personal checks so he can write future offers.Is this a strategic way to expedite the rehab-lending process?